Apparatus and process for making concrete pipe reinforcement member

ABSTRACT

Apparatus for and a process of welding and forming metal grid work into a reinforcing cage, having a driven mandrel and two idling mandrels, the latter of which are axially adjustable relative to each other and to the driven mandrel by means of a hydraulically actuated sleeve telescoping over the idling shaft and a hydraulically actuated carriage, respectively. One of the two idling mandrels bells the cage end, and this mandrel is recessed circumferentially to cooperate with a hand bending tool to complete the belling.

O United States Patent 1 3,661,186 Nordgren May 9, 1972 [54] APPARATUS AND PROCESS FOR [56] References Clted MAKING CONCRETE PIPE UNITED STATES PATENTS REINFORCEMENT MEMBER 2,091,540 8/1937 Whiting MO/92.2 Inventor: Alfred gr n. Holl nd. Mich. 3,437,114 4/!969 Whitacre et all 140/71 {73] Assignee: W. E. Dunn Manufacturing Company, Primaw wmmer lowe" A Larson Holland- AltorneyPrice, Heneveld. Huizenga & Cooper I22) Filed: Dec. 29.1969

ABSTRACT Appl' Nod s88'466 Apparatus for and a process of welding and forming metal grid work into a reinforcing cage, having a driven mandrel and two 52] us CI 140/107, 140/1 [2 idling mandrels. the latter of which are axially adjustable rela [5]] Int Cl B2 [5/08 Ennis/00 tive to each other and to the driven mandrel by means of a I I t l f Field of Search lllllllllllllll 92.2 l hydrau ically actuated s eeve te escopmg over he idling sha t and a hydraulically actuated carriage, respectively. One of the two idling mandrels bells the cage end, and this mandrel is recessed circumferentially to cooperate with a hand bending tool to complete the belling.

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M mm mm 1W 3 W F 6 LE mm" 5 APPARATUS AND PROCESS FOR MAKING CONCRETE PIPE REINFORCEMENT MEMBER BACKGROUND OF THE INVENTION This invention relates to apparatus for making the wire cage which constitutes the reinforcement for concrete structures, and in particular, the generally cylindrical wire cage used in reinforced concrete pipes having a belled female end. Earlier techniques for fabricating such cages have involved shaping the female end either completely by hand, on a machine separate from the one used to weld together the grid work into the cage shape, or shaping it simultaneously while the grid work was welded in its entirety into the cage shape (See US. Pat. No. 1,847,078). The disadvantage of the first of these alternatives as opposed to a machine operation is apparent. The second alternative requires removal of the cage from the welding machine and installing it in a second machine. The third alternative is undesirable because it lacks the efficiency of preparing a pre-welded strip of grid work which can then be cut and seam welded, such as in US. Pat. No. 3,370,150, and then formed with the female end.

SUMMARY OF INVENTION This invention provides an apparatus for and process of welding a wire cage constructed from a grid work having free ends extending from one side, and thereafter belling it to form the female end without removing the cage from the apparatus. The apparatus comprises in combination a base, a first mandrel mounted at one end of the base, a second mandrel mounted on the base spaced from the first mandrel, the second mandrel being adjustable relative to said first mandrel, means on the base for adjusting the second mandrel and means for expanding the free ends of the grid. The expanding means, preferably, has a recessed opening which cooperates with a hand bending tool having a diameter less than the width of the recessed opening.

Accordingly, it is an object of this invention to provide an apparatus for welding a grid work into a wire cage and thereafter forming the female end without removing the wire cage from that apparatus.

It is a further object to provide an apparatus of the above character in which part of the formation of the female end is done by the apparatus rather than by hand.

Other objects and advantages of the invention will become apparent upon reference to the following drawings and detailed discussion.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a partially fragmented front elevation of the entire apparatus, except for the hand tool;

FIG. 2 is an enlarged partially sectioned elevation of the motor-driven mandrel comprising one end of the apparatus illustrated in FIG. 1;

FIG. 3 is a perspective view illustrating the expanding mandrel in its inoperative position on the carriage;

FIG. 4 is an enlarged section taken generally along the plane of lines III-Ill of FIG. 3 but illustrating the expanding mandrel in its operative position;

FIG. 5 is a perspective illustrating the cooperation of the expanding mandrel with the bending tool, some of the wires of the cage having been removed for clarity;

FIG. 6 is a perspective of the bending tool;

FIG. 7 is a schematic illustrating the hydraulic control system for the apparatus; and

FIG. 8 in its four parts, 8A, 88, 8C and 8D is a schematic illustration of the process of the belling of the wire cage.

DESCRIPTION OF THE PREFERRED EMBODIMENT The invention is utilized in the welding of a grid work into a wire cage and thereafier in forming the belled female end of the wire cage while on the same apparatus. The actual welding is done by a conventional hand tool, and by itself does not constitute part of the invention. The grid work which is to form the wire cage is also conventional and can be prepared for welding as taught in US. Pat. No. 3,370,150.

In accordance with this invention, when the wire grid is ready for seam welding to complete the cage, it is rolled up with free ends 9 (FIG. 8A extending beyond the last strand. The grid work is then suspended on two tapered mandrels rotatably mounted on a frame 10. The outer diameter of these mandrels approximates the desired inner diameter of the finished cage. It should be noted, in this regard, that this invention contemplates the provision of interchangeable man drels (both expansion and suspension) of varying diameters such that different sized cages may be fabricated on the same basic apparatus.

The mandrel I2 (FIG. 2) is bolted to a plate 14 on a drive shaft [6 which rotates within two bearings 18. To provide a backstop for the grid work which is slid onto the mandrel I2, an annular back plate 20 is attached to a cylindrical extension 22 of the mandrel 12. To make the height of the mandrel [2 adjustable, the bearings 18 are secured to two pairs of columns 24 joined by a plate 25, which columns telescope into two pairs of hollow columns 26. Two pins 28 are inserted into the columns 24 to secure them at the desired height.

At the other end of the base (FIG. 3), the grid work is suspended by a tapered mandrel 30. Mandrel 30 is bolted to a conical bearing 32 rotatably mounted on a necked down portion 33 of an idler shaft 34. Idler shaft 34, in turn, is bolted to housing 36. Other than the mounting and the shape of the bearing 32, the addition of a cylinder plate 38, and the lack of a back plate 20, the mandrel 30 is basically identical to the mandrel 12.

To provide vertical adjustability and insure that the axis of the idler shaft 34 is colinear with the axis of the drive shaft 16, the housing 36 is bolted to a frame consisting of two pairs of columns 39 which telescope, in a manner similar to those supporting the other mandrel I2, into two pairs of hollow columns 40. Pins 42 are inserted into the column 39 to maintain mandrel 30st the desired height.

To allow the mandrel 30 to move into cage supporting position, the columns 40 are not fixed to the base 10 as are the columns 26, but instead are attached to a carriage 44 which rides by means of roilers 46 on two rails 47. To assist in guiding the carriage 44, pipes 48 welded to the side thereof telescope into pipes 49 supported by the frame I0. Because of the adjustability of the carriage, the operator is able to position the mandrel 30 so that its back edge 50 lines up with the last circumferential strand of the grid work leaving the free ends 9 extending beyond (FIG. 8A). In this position, the grid work is tightened circumferentially around mandrels 12 and 30 and seam welded at positions 51 to form the cage.

To insert a cage grid into the apparatus, mandrel 30 is moved to the left as viewed in FIG. 3 by expansion of cylinder 30. One open end of the cage blank is then placed over mandrel 12, the cage blank moved into general axial alignment with mandrel 30, and the carriage moved to the right such that mandrel 30 engages the remaining open cage end. The facing tapered extremities of mandrels I2 and 30 assist in the loading process by camming the cage blank into proper axial alignment as the mandrels are drawn together. The blank is then tightened circumferentially about mandrels l2 and 30 and welded. Unloading of the finished cage and reloading of another blank is accomplished, of course, by repeating this process.

In accordance with another aspect of this invention, a third mandrel 52, an expanding mandrel, is also rotatably mounted on the idler shaft 34 coaxially with the mandrel 30. The mandrel 52 tapers to a front edge 53 and is bolted to a mount 54 which rotates on a flanged sleeve 56 by means of two annular bearings 58 and 59, and a conical bearing 60 sandwiching the flange 61. The taper angle of the third mandrel equals the desired angle of divergence of the bell to be formed as will become apparent.

The third mandrel is axially slideable relative to the second mandrel 30. To achieve such slideability, a sleeve 56 is slideably positioned over idler shaft 34 within the housing 36 by means of a cylindrical bearing 62. The sleeve 56 and bearing 62 are limited in the extent of their reciprocation by slots 57 which abut the pins 37 at their extreme points of travel.

To actuate the expanding mandrel so as to move it from its inoperative position (FIG. 3) into position with the front edge 53 of the mandrel 52 abutting the back edge 50 of the mandrel 30, the piston rod 63 of a hydraulic cylinder is secured to stationary shaft 34. The cylinder housing 101 is affixed to sleeve 56 by means of a pad 64. When the cylinder is actuated, as will be readily apparent, expansion of rod 63 from housing 101 causes the sleeve 56 and attached mandrel 53 to slide to the left (FIG. 4) with respect to mandrel 30. When the cylinder is contracted, of course, the expanding mandrel returns toward its FIG. 4 position.

In accordance with still another aspect of this invention, the free ends 9 of the cage are next bent into the final bell shape shown in FIG. 8C by means ofa hand tool 66 (FIGS. and 6) while the cage is still suspended on the three mandrels. To accommodate the hand tool, the expanding mandrel 52 has a recessed opening 68 extending around the entire circumference of its back portion 70. The hand tool 66 includes two handle portions 72 and 73 welded at an angle to provide greater leverage. To grip the wire, an end 74 opposite the handle 73 is provided with a U-shaped opening 76 with substantially the same diameter as the wire strand. To insure that the hand tool will fit into the recessed opening 68, the width of the bar comprising the end portion 74 is less than the width of the recessed opening 68. To bring each of the free strands 9 into position for bending with the hand tool, the drive shaft I6 is indexed a few degrees, so that the mandrels and the cage rotate, and each free end is bent into its final position as illustrated in FIG. 8C.

Thereafter, a reinforcement wire 78 is wrapped around the belled female end by welding a wire to one of the free strands 9 as finally bent, and rotating the drive shaft for the requisite number of windings. The other end of the wrapping wire is then welded and intermediate welds are made along the wrapped wire where desired, so that the final wire cage (FIG. 8D) is ready for use in reinforced concrete pipes.

The operation of the apparatus is controlled hydraulically by conventional devices as indicated in FIG. 7. A cylinder 80 reciprocates the carriage 44 and the cylinder 65 reciprocates the sleeve 56 carrying the mandrel 52. A hydraulic motor 84 rotates the drive shaft 16. To actuate the motor 84 and the cylinders 80 and 65, switches S and S, and 5,, respectively, are provided, each comprising a conventional two-way spool valve mechanically shifted between its positions be means such as a pedal.

As is apparent from the foregoing description, the process of forming the belled wire cage comprises the positioning on the two mandrels 12 and 30 of a rolled-up grid work having its free ends 9 extending from one end, seam-welding the grid work to complete the formation of a cage; inserting a third mandrel 52 into the aforesaid end of the grid work to expand the free ends 9 away from the mandrel 52; bending with the hand tool 66 a portion of one of the free ends 9 so expanded back toward the mandrel; indexing the cage by means of the motor 84 so as to bring the next free end into position for bending; bending a portion of that next free end with the hand tool; continuing the alternating steps of indexing the motor and bending with the hand tool until the belled female end is formed; and wrapping by rotating the cage through the operation of the motor 84, the belled female end with a welded wire to reinforce it.

While the invention has been described in connection with preferred embodiments, it will be understood that I do not intend to cover all alternatives, modifications, and equivalents as may be included within the spirit and scope of the invention as defined by the following claims.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows.

1. Apparatus for making a belled wire cage utilized in forming reinforced concrete pipes, the cage being constructed from a grid work having ends extending from one side, said apparatus comprising:

a base;

a first mandrel having a cage supporting section mounted at one end of said base;

a second mandrel having a cage supporting section mounted on said base at a position spaced from said first mandrel, the position of said second mandrel being adjustable relative to said first mandrel;

means on said base for adjusting the relative spatial relationship of said mandrels;

means shiftable relative to said first and second mandrels for expanding the ends of the grid away from said axes; and

means for actuating said expanding means.

2. The apparatus as set forth in claim 1 wherein said first and second mandrels are rotatably mounted in coaxial fashion upon said base and which further comprises means for rotating one of said mandrels.

3. The apparatus as set forth in claim 2 wherein the position of said second mandrel is adjustable relative to said first mandrel along a line coinciding with the axes of rotation of said first and second mandrels.

4. The apparatus as defined in claim 3 wherein:

said adjusting means includes a rail fixed to said base and a carriage movably mounted on said rail; and

said expanding means includes a third mandrel rotatably mounted on said carriage coaxially with said first and second mandrels, said third mandrel being axially shiftable relative to said first and second mandrels.

5. The apparatus as set forth in claim 4 which further comprises a shaft means mounted upon said carriage, said second and third mandrels being mounted upon said shaft means for rotation and for relative sliding movement.

6. The apparatus as set forth in claim 5 wherein said third mandrel includes a tapered portion for engaging and expanding the ends of said grid.

7. The apparatus as set forth in claim 6 wherein said third mandrel is recessed radially about its perimeter.

8. The apparatus as set forth in claim 6 wherein said actuating means comprises a hydraulic cylinder.

9. In combination with the apparatus as defined in claim 7, a bending tool comprising an elongated member having at one end a U-shaped opening and at the other end a handle, the member having a thickness at the U-shaped end thereof which is less than the width of the recess in said third mandrel.

10. The combination as defined in claim 9 wherein said handle has welded transversely to it a second handle.

11. The process of making a belled wire cage utilized in forming reinforced concrete pipes, comprising the steps of:

positioning on two mandrels a rolled-up grid work having free ends extending from one end;

seam-welding the grid work to form a cage;

inserting a third mandrel into said end of the grid work to expand the free ends away from the mandrel;

bending a portion of one of the free ends so expanded back toward the mandrel.

12. The process as set forth in claim 11 which further comprises the steps of:

indexing the cage to bring the next free end into position for bending;

bending a portion of the next expanded free end back toward the mandrel; and

continuing the alternating steps of indexing and bending until the belled female end is formed.

l3v The process as defined in claim l2 and further including the step of wrapping the formed belled female end to reinforce it.

t I i i l 

1. Apparatus for making a belled wire cage utilized in forming reinforced concrete pipes, the cage being constructed from a grid work having ends extending from one side, said apparatus comprising: a base; a first mandrel having a cage supporting section mounted at one end of said base; a second mandrel having a cage supporting section mounted on said base at a position spaced from said first mandrel, the position of said second mandrel being adjustable relative to said first mandrel; means on said base for adjusting the relative spatial relationship of said mandrels; means shiftable relative to said first and second mandrels for expanding the ends of the grid away from said axes; and means for actuating said expanding means.
 2. The apparatus as set forth in claim 1 wherein said first and second mandrels are rotatably mounted in coaxial fashion upon said base and which further comprises means for rotating one of said mandrels.
 3. The apparatus as set forth in claim 2 wherein the position of said second mandrel is adjustable relative to said first mandrel along a line coinciding with the axes of rotation of said first and second mandrels.
 4. The apparatus as defined in claim 3 wherein: said adjusting means includes a rail fixed to said base and a carriage movably mounted on said rail; and said expanding means includes a third mandrel rotatably mounted on said carriage coaxially with said first and second mandrels, said third mandrel being axially shiftable relative to said first and second mandrels.
 5. The apparatus as set forth in claim 4 which further comprises a shaft means mounted upon said carriage, said second and third mandrels being mounted upon said shaft means for rotation and for relative sliding movement.
 6. The apparatus as set forth in claim 5 wherein said third mandrel includes a tapered portion for engaging and expanding the ends of said grid.
 7. The apparatus as set forth in claim 6 wherein said third mandrel is recessed radially about its perimeter.
 8. The apparatus as set forth in claim 6 wherein said actuating means comprises a hydraulic cylinder.
 9. In combination with the apparatus as defined in claim 7, a bending tool comprising an elongated member having at one end a U-shaped opening and at the other end a handle, the member having a thickness at the U-shaped end thereof which is less than the width of the recess in said third mandrel.
 10. The combination as defined in claim 9 wherein said handle has welded transversely to it a second handle.
 11. The process of making a belled wire cage utilized in forming reinforced concrete pipes, comprising the steps of: positioning on two mandrels a rolled-up grid work having free ends extending from one end; seam-welding the grid work to fOrm a cage; inserting a third mandrel into said end of the grid work to expand the free ends away from the mandrel; bending a portion of one of the free ends so expanded back toward the mandrel.
 12. The process as set forth in claim 11 which further comprises the steps of: indexing the cage to bring the next free end into position for bending; bending a portion of the next expanded free end back toward the mandrel; and continuing the alternating steps of indexing and bending until the belled female end is formed.
 13. The process as defined in claim 12 and further including the step of wrapping the formed belled female end to reinforce it. 